Panel

ABSTRACT

A panel including a core, a top side, an underside, a first edge pair and a second edge pair. The first edge pair has a groove profile at a panel edge and a complementary tongue profile at the opposite panel edge, which are lockable by a pivotal movement so that in the locked state vertical locking is achieved and movement of locked panels away from each other in the plane of the panels is opposed. At its opposite panel edges the second edge pair has a receiving hook and a complementary arresting hook. The arresting hook can be assembled to the receiving hook by a joining movement in a plane perpendicular to the panel plane simultaneously by the pivotal movement for the first edge pair. The receiving hook or the arresting hook has a holding groove for a separate locking element that provides vertical locking. A butting surface and a counterpart butting surface are provided at least at the second edge pair. The butting surface is at the receiving hook and the counterpart butting surface is at the arresting hook and both are substantially orthogonally relative to the panel top side. The counterpart butting surface or the butting surface has at least one sealing nipple. The butting surface or the counterpart butting surface has at least one sealing groove matching the sealing nipple in positively locking relationship at the panel edge and the sealing nipple and the sealing groove are respectively arranged parallel to the panel edge in question and extend over the entire length of the butting surface and the counterpart butting surface respectively.

The invention concerns a panel comprising a panel core, a panel top side, a panel underside and a first edge pair and a second edge pair, wherein the first edge pair is provided with a groove profile at a panel edge and a tongue profile complementary thereto at the opposite panel edge, which are lockable by a pivotal movement and then cooperate in positively locking relationship in such a way that in the locked state a vertical locking action can be achieved and a movement of locked panels away from each other in the plane of the panels (horizontally) is opposed, wherein at its opposite panel edges the second edge pair is provided with complementary hook profiles, namely a receiving hook and an arresting hook, wherein the arresting hook can be assembled to the receiving hook by a joining movement in a plane perpendicular to the panel plane simultaneously by means of the pivotal movement for the first edge pair, with the proviso that the receiving hook is provided with a holding groove for a separate locking element with which a vertical locking action can be achieved, wherein a butting surface and a counterpart butting surface are provided at least at the second edge pair, with the proviso that the butting surface is arranged at the receiving hook and the counterpart butting surface is arranged at the arresting hook and both are arranged substantially orthogonally relative to the panel top side.

A panel of the general kind set forth is known from EP 1 415 056 B1. This is a panel which includes a first edge pair with a tongue-and-groove profile and a second edge pair with hook profiles. In that way the known panel can be locked at an edge with the tongue profile to the groove profile of the panels of a preceding row of panels by means of a pivotal movement; it is viewed as a great advantage that one of the edges with the hook profile can also be locked at the same time by means of the above-mentioned pivotal movement. In that situation the separate locking element latches of its own accord. The latching function of the locking element is automatically triggered by the above-mentioned pivotal movement at the first edge pair of the panel.

That panel laying mode is also referred to as fold-down laying or the appropriate panel is referred to as a fold-down panel.

Panels of that kind are connected together in rows, in which case there are transverse joins between the panels within a row. In addition longitudinal joins are respectively formed between the rows of panels of a laid coverage surface which is formed in combined relationship in that way. It is desirable that the longitudinal joins and transverse joins of such a coverage surface are to afford a certain degree of sealing integrity to prevent water from passing therethrough. In practice it has unfortunately been found that water can penetrate into joins and in places can flow from the panel top side through the join to the panel underside. Water which penetrates into the join or passes therethrough in that way can lead to the formation of mold which can spread concealed under a coverage surface.

It has been found in that case that moisture can penetrate or pass through in particular by way of the transverse edge and the intersections of transverse and longitudinal edges.

The object of the invention is to propose a panel which is of an improved configuration at least in respect of the profiles of the second edge pair in order better to resist water passing through at the joins.

According to the invention that object is attained in that the counterpart butting surface of the arresting hook or the butting surface of the receiving hook is provided with at least one sealing nipple, the butting surface of the receiving book or the counterpart butting surface of the arresting hook is provided with at least one sealing groove matching the sealing nipple in positively locking relationship at the panel edge and the sealing nipple and the sealing groove are respectively arranged parallel to the panel edge in question and extend over the entire length of the butting surface and the counterpart butting surface respectively.

The proposed panel is provided with a sealing measure which is provided spatially physically in the region of the respective joins. More specifically the combination provided at the second edge pair comprising the sealing nipple and the sealing groove effectively prevents the ingress of water or prevents water from passing through the join.

The proposed panel is of a quadrangular basic shape. At one of the four corners of the panel the tongue profile of the first edge pair comes together with the receiving hooks of the second edge pair. Those two differing forms of the panel edges overlap in that corner whereby this results in an overlap zone in respect of the different profile shapes, in which there is a complex three-dimensional configuration. That complex configuration therefore means that the receiving hook must have the holding groove for the locking element and for that reason that holding groove comes together at the corner with the tongue profile of the adjoining panel edge of that corner. To manufacture the holding groove material of the panel core has to be removed, for example by milling. The milling of the holding groove passes through the tongue profile at an end (transitional zone) and machines a part of the panel core, that formed the tongue. A part of the material of the tongue profile is therefore machines and removed. A gap is produced at the tongue top side in that transitional zone, and no water may pass through to that gap. For that reason the proposed design configuration pursues the technical path of providing above the tongue top side suitable measures which effectively resist the ingress of water as far as the level of the tongue top side. It has been found that it is possible to achieve better sealing integrity in relation to water passing therethrough in that way.

Easily the cross-section of the holding groove can be retained for the separate locking element and a known locking element can be used. Suitable locking elements are known for example from EP 1 415 056 B1, WO 2011/087425 A1, U.S. Pat. No. 9,347,469 B2 or U.S. Pat. No. 7,866,110 B2. Reference is hereby made to the examples of design configurations for separate locking elements and the arrangement thereof on a panel, as defined in the above-mentioned publications, and that technical teaching is incorporated herein. The separate locking element for the complementary hook profiles can optionally be provided as a constituent part of the panel. The locking element is preferably then pre-fitted in the holding groove of the receiving hook.

Advantageously the carrier plate forming the basis of a panel according to the invention has a fiber material like for example a high-density fiber material (HDF) or a medium-density fiber material (MDF), an oriented strand board (OSB) or a wood-plastic composite material (WPC). It can also be provided that the panel has a decoration, in which case that decoration can be provided either by applying a decorative layer which has already been printed to a carrier plate or by direct printing of the carrier plate with such a decoration. In that respect in the present case the term direct printing is also used to mean printing of a printing background previously applied to a carrier plate. It can also be provided that the panel comprises a full wood material or is formed completely from a wood material. Advantageously such a fiber material can absorb water or liquid in the case of coming into contact with moisture, and that leads to swelling. In that case such swelling leads to an improved sealing closure in the region of the sealing nipple or the butting surface and the counterpart butting surface. In a further embodiment of the invention the carrier plate forming the basis for a panel according to the invention has a plastic material like for example a polypropylene (PP), polyethylene (PE), polyethylene-terephthalate (PET), an acrylonitrile-butadiene-styrene-copolymer (ABS), a polyvinyl chloride (PVC), a polycarbonate (PC), a polyamide (PA), a polyetherketone (PEK), polyetheretherketone (PEEK), mixtures or copolymers thereof, or a plastic composite material comprising one or more of said plastics with a fiber and/or mineral filler.

The complementary hook profiles of the second edge pair, namely the upwardly open receiving hook and the downwardly open arresting hook advantageously have on both sides holding surfaces provided in one piece on the panel core, by means of which the locking action to prevent the panels from moving away from each other within the panel plane in a direction perpendicular to the locked panel edges can be achieved. The locking action in the vertical direction which is perpendicular to the panel top side is particularly user-friendly and can be easily achieved by means of the separate locking element.

Desirably at least one of the edge pairs at the two complementary panel edges thereof has a respective edge break which in the assembled state of two of those panels forms a recessed join.

Preferably the edge breaks of at least one of the edge pairs at the complementary panel edges thereof are of differing sizes so that in the assembled state the larger edge break is covered over by the smaller edge break.

In addition it is possible to achieve an improvement in the sealing integrity by the provision at each panel edge having the smaller edge break of a projection, on the top side of which there extends at least a part of the smaller edge break, while provided at an underside of the projection is an undercut counterpart surface for the covered-over part of the larger edge break.

It is desirable that the smaller edge break of the first edge pair is arranged at the groove profile and the larger edge break is arranged at the tongue profile and that the smaller edge break of the second edge pair is arranged at the arresting hook and the larger edge break is arranged at the receiving hook.

Furthermore it is advantageous if at the first edge pair and/or at the second edge pair the counterpart butting surface is inclined relative to the orthogonal on the panel top side through an angle in the range of 1°-5°, wherein the cross-section of the arresting hook in the inclined region of the counterpart butting surface has an oversize and/or the cross-section of the groove profile in the inclined region of the counterpart butting surface has an oversize so that in the locked state a pressing action can be caused between the counterpart butting surface and the butting surface. The term “oversize” relates to the relationship of the two panel edges which can be assembled together. Starting from a theoretical nominal dimension of the two panel edges the term “oversize” is used to mean that, starting from the nominal size, more material is present either at the butting surface and/or at the counterpart butting surface so that the surface of the butting surface and/or the surface of the counterpart butting surface projects distally further than the nominal dimension. In practice this can be a maximum oversize by hundredths to a few tenths of a millimeter, which in practice produces the desired pressing action between the butting surface and the counterpart butting surface of the assembled panel edges. That desired pressing effect appropriately occurs in the upper region of the butting surface and the counterpart butting surface and can extend for example over half the height of the butting surface or counterpart butting surface.

An advantageous development provides that the pressing action between the counterpart butting surface and the butting surface is greater at the upper end of the butting surface and decreases towards the lower end of the butting surface.

An alternative provides that the holding groove for the separate locking element has parallel groove walls, wherein the groove walls are at a constant spacing relative to each other.

It is further helpful if the holding groove or the groove walls of the holding groove are arranged inclinedly relative to the panel top side. It is further desirable if the free opening of the inclinedly arranged holding groove is directed upwardly, that is to say in the direction of the panel top side. It is useful for a closed join if the separate locking element has a latching means with which it can be automatically latched in a latching recess in the complementary panel edge.

The invention is described in detail hereinafter by means of a number of embodiments and illustrated by way of example in a drawing in which:

FIG. 1 shows a diagrammatic view of a plurality of panels according to the invention in combination,

FIG. 2 shows by way of example a cross-section through a first edge pair of a panel according to the invention in the locked state,

FIG. 3 shows a cross-section through the second edge pair of the panel according to the invention in the locked state,

FIG. 4 shows a perspective view of two panel portions having the panel edges of FIG. 2 in the locked state and with the tongue profile shown in FIG. 1 ,

FIG. 5 shows a perspective view of two panel portions in the locked state with an alternative separate locking element,

FIG. 6 shows an alternative cross-section through a first edge pair of a panel according to the invention in the locked state,

FIG. 7 shows an alternative cross-section through the second edge pair of a panel according to the invention in the locked state,

FIG. 8 shows a further example of a cross-section through a second edge pair of the panel according to the invention in the locked state,

FIG. 9 shows yet another example of a cross-section through the second edge pair of the panel according to the invention in the locked state,

FIG. 10 shows a further alternative of a cross-section through the second edge pair of the panel according to the invention in the locked state, and

FIG. 11 shows a last example of a cross-section through the second edge pair of the panel according to the invention in the locked state.

FIG. 1 diagrammatically shows portions of four identical panels 1, 2, 3 and 4 according to the invention, more specifically assembled in combination to form a coverage surface. The coverage surface can be used for a building wall, ceiling or a floor. Each of the panels according to the invention respectively has four panel edges F, M, N and U and four corners K1, K2, K3 and K4. As can be seen from the following Figures the panel has a panel top side 7, a panel underside 8 and a panel core 9. The panel has two edge pairs. A first edge pair is shown by way of example in FIG. 2 and includes the panel edges N and F, wherein the panel edge N has a groove profile 5 and the panel edge F has a tongue profile 6.

A second edge pair is shown in FIG. 3 and includes the panel edges M and U which are in the form of hook profiles. The panel edge M is in the form of a receiving hook 10 and the panel edge U in the form of an arresting hook 11. The receiving hook 10 is provided with a holding groove 12 for a separate locking element 13. The locking element 13 is fitted and used in such a way that it locks in the vertical direction (vertical locking element). The arresting hook 11 can be connected to the receiving hook 10 by means of a joining movement in a vertical plane downwardly. If a vertical locking element 13 is used the vertically acting locking effect takes place automatically, as is described in detail hereinafter with reference to FIG. 3 . By virtue of the two different edge pairs the proposed panel is suitable for locking by a pivotal movement (fold-down). The pivotal movement is indicated in FIG. 2 by reference to the panel 4 which is shown in broken line in an inclined starting position 4′. The panel 4 is moved down from its starting position 4′ in the direction of the pivotal arrow S by a single downwardly pivotal movement about its panel edge F as the axis of rotation. In that situation it locks with the groove profile 5 of the panels 1 and 2 of a preceding row of panels P1. At the same time the panel edge U of the panel 4 is locked to the panel edge M of the panel 3 which is in the same row of panels P2.

As shown in FIG. 1 at a corner K1 of the panel 4, the panel edge F (first edge pair) meets the panel edge U (second edge pair). That corner K1 is found to be particularly critical in regard to sealing integrity of the coverage surface in relation to water passing therethrough. At the critical corner K1 the tongue profile 6 of the panel edge F meets the arresting hook 11 of the panel edge U.

The cross-sections of the tongue profile 6 and the arresting hook 11 overlap spatially and that affords a complex spatial configuration at the corner K1.

In combination with further identical panels 1 and 3 the corner K1 in question of the panel 4 is disposed in a region marked by IV. There a T-join is formed, composed of a longitudinal join (panel edges F/N) and a transverse join (panel edges M/U). A view on to that T-join in the viewing direction indicated by the arrow IV is described in detail hereinafter with reference to FIG. 4 .

Referring to FIG. 2 this shows the first edge pair of the panel according to the invention in cross-section. The direction of view corresponds to the section line II-II shown in FIG. 1 . The panel edges F and N of the panels 1 and 4 are opposite in FIG. 2 as indicated in FIG. 1 by means of the section line II-II. The panel edge F has a tongue profile and the panel edge N has a complementary groove profile. Those complementary panel edges F/N can be shown portion-wise in the locked state, as if the panel is divided into two parts. That form of illustration is intended to make it easier to understand the functionality and cooperation of the complementary panel edges. A starting position 4′ of the panel edge F indicates a pivotal movement S. It will be appreciated that a plurality of panels of the kind according to the invention can be locked together in the same way to produce a coverage surface for a building wall, a floor or a ceiling. For that reason FIGS. 2 and 3 can also each be viewed as being two panels which are shown portion-wise.

The panel edge M in the form of the receiving hook 10 and the panel edge U in the form of the arresting hook 11 of the second edge pair are shown in cross-section in FIG. 3 , more specifically also in the assembled locked state. The direction of view corresponds to the section line shown in FIG. 1 .

At the second edge pair the arresting hook 11 of the panel edge M at the panel top side 7 has an edge break in the form of a larger chamfer 36 and the receiving hook 10 of the panel edge U is provided with a smaller chamfer 37.

The smaller chamfer 37 extends over a distal projection 38 arranged distally on the arresting hook 11. An underside of the projection forms a counterpart surface 39 which in the locked state covers over a part of the larger chamfer 36 and is in contact with that part so that this gives a first seal in relation to the ingress of water. In the locked state the two chamfers form a V-shaped join 40.

The receiving hook 10 and the arresting hook 11 lock the assembled panel edges M/U in the vertical and also in the horizontal direction. To give the vertical locking action in this embodiment a separate locking element 13 (vertical locking element) can be fitted into the holding groove 12 in the receiving hook 10, that is provided for that purpose. Provided on the arresting hook 11 is a latching recess 11 a into which the locking element 13 can latch. The latching recess has an inclined lower groove wall 11 b and an inclined upper groove wall 11 c.

The holding groove 12 that is provided in the receiving hook 10 for the locking element 13 is provided with a flat lower groove wall 12 a, an upper groove wall 12 b and a groove bottom 12 c. The upper groove wall 12 b has a step 12 d so arranged that there is a narrower part of the holding groove 12 facing towards the groove bottom 12 c and a region of a greater width, directed towards the open side of the holding groove 12.

The configuration of the holding groove 12 with the step 12 d is adapted to the known locking element 13, the cross-section of which is shown by way of example in FIG. 3 . In the case of the illustrated hatched locking element 13 a latching means 13 a is provided in the form of an inclinedly downwardly projecting latching tab 13 b projecting out of the holding groove 12. In addition the locking element 13 includes a holding means 13 c which faces towards the groove bottom 12 c of the holding groove 12, and a shoulder 13 d supported against the step 12 d of the upper groove wall. Suitable locking elements are known for example from the following publications: EP 1 415 056 B1, WO 2011/087425 A1 and US 2014/0366476 A1.

For the horizontal locking action, as shown in FIG. 3 , the receiving hook 10 of the panel edge M is provided distally with a hook edge 41 projecting in the direction of the panel top side 7, and with a receiving recess 42 which is open towards the panel top side 7. The arresting hook 11 of the panel edge U has an arresting step 43 projecting in the direction of the panel underside 8 and a downwardly open arresting recess 44. The arresting step 43 fits into the receiving recess 42 of the receiving hook 10 and cooperates therewith.

The receiving hook 10 has at the hook edge 41 a holding surface 45 directed towards the panel core 9. Equally provided on the arresting hook 11 is a holding surface 46 which is also directed towards the panel core 9 and which with the holding surface 45 on the hook edge 41 affords an undercut configuration and thus provides a locking action to prevent the panels 3 and 4 from moving away from each other within the panel plane in a direction perpendicular to the locked panel edges M/U (horizontally).

In the present example, at a step underside 47, the arresting step 43 has a distal step surface 48 which is in contact with a bottom 49 of the receiving recess 42, and a proximal recess 50 which extends laterally as far as the holding surface 46 of the arresting step 43. The recess 50 uses good contact in respect of the holding surfaces 45/46 of the hook edge 41 and the arresting step 43.

Within the locking configuration shown in FIG. 3 it is also possible to see pairs of contact surfaces, wherein a respective surface of the arresting hook 11 is in contact with an associated surface of the complementary receiving hook 10. In a direction from above downwardly through the locking configuration that begins with a first contact surface pairing which is formed from the counterpart surface 39 of the projection 38 of the arresting hook and the covered part of the larger chamfer 36 which is arranged on the receiving hook 10.

The next contact surface pairing is formed from a butting surface 10 a and a counterpart butting surface 11 d. The butting surface 10 a is provided on the receiving hook 10 with the panel edge M beneath the large chamfer 36 and the counterpart butting surface 11 d is provided on the arresting hook 11 of the panel edge N below the small chamfer 37. In this arrangement the butting surface 10 a is arranged perpendicularly relative to the panel top side 7 and the counterpart butting surface 11 d is inclined relative to the orthogonal to the panel top side 7 through an angle of 3°. In that case provided at an upper part of the counterpart butting surface 11 d is a material excess which is shown in broken line in FIG. 3 as an oversize E2. In the locked state the oversize E2 leads to a pressure effect between the contact surface pairing comprising the butting surface 10 a/counterpart butting surface 11 d, more specifically in the upper half of that contact surface pairing. That pressing action also provides a sealing effect.

FIG. 4 shows an isometric view of two connected panels 3 and 4. The view corresponds to the direction of view IV as noted in FIG. 1 . In the foreground of FIG. 4 it is possible to see the tongue profiles F of the panels 3 and 4. The panel edge M of the panel 3 and the panel edge U of the panel 4 extend rearwardly in the perspective view. The panel edge M is provided with the receiving hook 10 and the panel edge U is provided with the arresting hook 11 shown in FIG. 3 .

Provided on the complementary panel 4 is the latching recess 11 a in which the locking element 13 can automatically latch. The latching recess 11 a also extends on the panel 4 through the tongue profile 6 and ends in the form of an open cross-section at the tongue tip 19.

The arresting hook 11 (panel edge U) of the panel 4 also includes the downwardly open arresting recess 44 shown in cross-section in FIG. 3 . The arresting recess 44 also extends transversely through the tongue profile of the panel 4 and issues in the lower region of the tonge profile. The open cross-section of the arresting recess 44 issues beneath the tongue tip.

FIG. 5 shows a perspective view of two panel pieces of an alternative embodiment of the panel. It differs from FIG. 4 because it is designed for an alternative locking element 52. A holding groove 53 of rectangular cross-section is provided for that locking element 52 on the receiving hook 10, wherein the locking element 52 can be pre-fitted into the holding groove. The holding groove 53 has an upper groove wall 54 arranged at a spacing R2 from the panel top side 7. The arresting hook 11 also has a latching contour which is in the form of a locking groove 55 and the cross-section of which is correspondingly adapted so that the locking element 52 can automatically come into latching engagement there. The holding groove 53 proposed in FIG. 5 is adapted for the use of an arcuate locking element 52 as is known from US 2014/0366476 A1 (FIG. 3b) or is adapted for a locking element known from the same document with rearward resilient bristles (FIG. 6a or FIG. 6b) which bear against the bottom of the holding groove 53.

FIG. 6 shows an alternative cross-section through a first edge pair of a panel according to the invention in the locked state. The panel has a panel edge F with a tongue profile and a panel edge N with a groove profile. The two panel edges F and N are locked in positively locking relationship by the illustrated configuration of the panel edges, more specifically both in the vertical and in the horizontal directions.

FIG. 7 shows an alternative cross-section through the second edge pair of the panel according to the invention in the locked state. This example includes a receiving hook 56 at a panel edge M and an arresting hook 57 at a panel edge U. A holding groove 58 for a locking element 59 is provided in the receiving hook. The arresting hook 57 has a contour 60, into which the locking element 59 can automatically latch. The holding groove 58 for the locking element 59 is arranged substantially parallel to the panel top side 7. Provided on the arresting hook 57 is a sealing nipple G2 which fits together with and seals a sealing groove W2 on the receiving hook 56. The contact takes place directly above and near to the holding groove 58 of the receiving hook 56.

FIG. 8 shows a further example of a second edge pair. Once again there is a receiving hook 62 on a panel edge M and an arresting hook 63 on a panel edge U. The receiving hook 62 includes a holding groove 64 for a locking element 65 and the arresting hook has a contour 66 in which the locking element 65 can automatically latch. As a difference in relation to the FIG. 7 example here the holding groove 64 is arranged inclinedly in the receiving hook 62 relative to the panel top side 7. Provided on the arresting hook 63 is a sealing nipple G2 which fits together with and seals a sealing groove W2 provided on the receiving hook 62.

FIG. 9 shows yet another example of a cross-section through the second edge pair of the panel according to the invention in the locked state. That example also has a receiving hook 68 at a panel edge M and an arresting hook 69 at a panel edge U, which can be automatically locked in the vertical direction by means of a locking element 70. In this example there is a holding groove 71 for the locking element 70 but on the arresting hook 69 and the receiving hook 68 has a contour 72, into which the locking element 70 can automatically latch. Here provided on the receiving hook 69 is a sealing nipple G3 which fits together with and seals a sealing groove W3 provided on the arresting hook 68.

FIG. 10 shows a further alternative of a cross-section through the second edge pair. This example again has a receiving hook 74 and an arresting hook 75 which can be locked automatically in the vertical direction by means of a locking element 76. As in FIG. 9 in this example too there is a holding groove 77 for the locking element 76 on the arresting hook 75. The receiving hook 74 has a contour 78 into which the locking element 76 can automatically latch. Here also there is provided a sealing nipple G3 on the receiving hook 74, which fits together with and seals a sealing groove W3 provided on the arresting hook 75.

FIG. 11 shows a last example of a second edge pair in cross-section. It is based on the example shown in FIG. 3 , wherein as a difference in relation thereto two sealing nipples G2 and G4 are arranged on the arresting hook. In matching relationship therewith the receiving hook has two sealing grooves W2 and W4 which together with the sealing nipples G2 and G4 provide for improved sealing integrity in relation to the ingress of water or water passing therethrough.

LIST OF REFERENCES

-   -   1 panel     -   2 panel     -   3 panel     -   4 panel     -   5 groove profile     -   5 a inner surface (upper groove wall)     -   6 tongue profile     -   7 panel top side     -   8 panel underside     -   9 panel core     -   10 receiving hook     -   10 a butting surface     -   11 arresting hook     -   11 a latching recess     -   11 b lower groove wall     -   11 c upper groove wall     -   12 holding groove     -   12 a lower groove wall     -   12 b upper groove wall     -   12 c groove bottom     -   12 d step     -   13 locking element     -   13 a latching means     -   13 b latching tab     -   13 c holding means     -   13 d shoulder     -   36 larger chamfer     -   37 smaller chamfer     -   38 projection     -   39 counterpart surface     -   40 V-join     -   41 hook edge     -   42 receiving recess     -   43 arresting step     -   44 arresting recess     -   45 holding surface (hook edge)     -   46 holding surface (arresting hook)     -   47 step underside     -   48 distal step surface     -   49 bottom     -   50 recess     -   52 locking element     -   53 holding groove     -   54 upper groove wall     -   55 locking groove     -   56 receiving hook     -   57 arresting hook     -   58 holding groove     -   59 locking element     -   60 contour     -   62 receiving hook     -   63 arresting hook     -   64 holding groove     -   65 locking element     -   66 contour     -   68 receiving hook     -   69 arresting hook     -   70 locking element     -   71 holding groove     -   72 contour     -   74 receiving hook     -   75 arresting hook     -   76 locking element     -   77 holding groove     -   78 contour     -   D spacing     -   E1 oversize     -   E2 oversize     -   F panel edge (tongue)     -   G2 sealing nipple (arresting hook)     -   G3 sealing nipple (receiving hook)     -   G4 sealing nipple (arresting hook)     -   H height     -   K1 corner     -   K2 corner     -   K3 corner     -   K4 corner     -   L panel edge (groove)     -   M panel edge (receiving hook)     -   P1 row of panels     -   P2 row of panels     -   U panel edge (arresting hook)     -   S pivotal movement     -   W2 sealing groove (receiving hook)     -   W3 sealing groove (arresting hook)     -   W4 sealing groove (receiving hook) 

1-9. (canceled)
 10. A panel comprising a panel core, a panel top side, a panel underside and a first edge pair and a second edge pair, wherein the first edge pair is provided with a groove profile at a panel edge and a tongue profile complementary thereto at the opposite panel edge, which are lockable by a pivotal movement and then cooperate in positively locking relationship in such a way that in the locked state a vertical locking action can be achieved and a movement of locked panels away from each other in the plane of the panels is opposed, wherein at its opposite panel edges the second edge pair is provided with complementary hook profiles, namely a receiving hook and an arresting hook, wherein the arresting hook can be assembled to the receiving hook by a joining movement in a plane perpendicular to the panel plane simultaneously by means of the pivotal movement for the first edge pair, with the proviso that the receiving hook is provided with a holding groove or the arresting hook is provided with a holding groove for a separate locking element with which a vertical locking action can be achieved, wherein a butting surface and a counterpart butting surface are provided at least at the second edge pair, with the proviso that the butting surface is arranged at the receiving hook and the counterpart butting surface is arranged at the arresting hook and both are arranged substantially orthogonally relative to the panel top side wherein the counterpart butting surface of the arresting hook or the butting surface of the receiving hook is provided with at least one sealing nipple, the butting surface of the receiving book or the counterpart butting surface of the arresting hook is provided with at least one sealing groove matching the sealing nipple in positively locking relationship at the panel edge and the sealing nipple and the sealing groove are respectively arranged parallel to the panel edge in question and extend over the entire length of the butting surface and the counterpart butting surface respectively.
 11. The panel according to claim 10, wherein at least one of the edge pairs at the two complementary panel edges thereof has a respective edge break which forms a recessed join in the assembled state of two of said panels.
 12. The panel according to claim 11, wherein the edge breaks of at least one of the edge pairs at the complementary panel edges thereof are of different sizes so that in the assembled state the larger edge break is covered over by the smaller edge break.
 13. The panel according to claim 12, wherein provided at that panel edge with the smaller edge break is a projection, on the top side of which extends at least a part of the smaller edge break, and that provided at an underside of the projection is an undercut counterpart surface for the covered-over part of the larger edge break.
 14. The panel according to claim 12, wherein the smaller edge break of the first edge pair is arranged at the groove profile and the larger edge break is arranged at the tongue profile and that the smaller edge break of the second edge pair is arranged at the arresting hook and the larger edge break is arranged at the receiving hook.
 15. The panel according to claim 10, wherein at the second edge pair the counterpart butting surface is inclined relative to the orthogonal to the panel top side by an angle in the range of 1°-5°, that the cross-section of the arresting hook has an oversize in the inclined region of the counterpart butting surface and/or the cross-section of the groove profile has an oversize in the inclined region of the counterpart butting surface so that in the locked state a pressing action can be caused between the counterpart butting surface and the butting surfaces.
 16. The panel according to claim 10, wherein the pressing action between the counterpart butting surface and the butting surface is greater at the upper end of the butting surface and decreases towards the lower end of the butting surface.
 17. The panel according to claim 10, wherein the separate locking element has a latching means with which it is latchable in a latching recess of the complementary panel edge.
 18. The panel according to claim 10, wherein the holding groove for the separate locking element has parallel groove walls. 